help with safe coil building

hi, been using SMOK xcube ultra for a while but just bought my first mech mod and RDA, looking for some clarification on safe coil building before i try anything.
first im using Sony VTC4 18650 2100mAh 30A batteries in a VGOD pro mech and VGOD pro drip RDA with 24g kanthal wire. I have used the online calculators to work out (i think) that .5 ohms at 4.2 volts should only be about an 8.4 amp draw which should be safe as i dont want to push batteries this new into the rebuilding game.
so my questions are
-how many wraps and diameter of coils would yield .5ohms on a single coil?
-how do i calculate safe usage with dual coil builds?
-if im starting at .5phms with 24g wire what would be a safe and decent next step?
any help would be great

Single, series or parallel?

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single

everything.else.is.taken said:

hi, been using SMOK xcube ultra for a while but just bought my first mech mod and RDA, looking for some clarification on safe coil building before i try anything.
first im using Sony VTC4 18650 2100mAh 30A batteries in a VGOD pro mech and VGOD pro drip RDA with 24g kanthal wire. I have used the online calculators to work out (i think) that .5 ohms at 4.2 volts should only be about an 8.4 amp draw which should be safe as i dont want to push batteries this new into the rebuilding game.
so my questions are
-how many wraps and diameter of coils would yield .5ohms on a single coil?
-how do i calculate safe usage with dual coil builds?
-if im starting at .5phms with 24g wire what would be a safe and decent next step?
any help would be great

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Wrapping around a 3mm bit/screwdriver, 5 full wraps should put you at around .48 Ω if you're using 24ga round kanthal. Dual Coil builds will split the resistance pretty much in half (ex: if you built 2 coils with 5 wraps of 24ga Kanthal around a 3mm bit, you would ohm out at around .24 Ω rather than .48 Ω). A good next step would be to try different wires out to see what you prefer...I, for one, can't stand the taste of Kanthal and use either Nichrome 80 or SS316L for all of my mech builds. But depending on what you like, you could step up to parallel builds or if you have access to a drill then you can try twisting wire and eventually Clapton and so on and so forth...welcome to the dark side!


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when you build dual coils you cut the ohms in half
so you build 2 identical coils
if each is .5 ohms then as a dual coil its only .25 ohms

using this
http://www.steam-engine.org/coil.html

you need about 5 wraps of 24ga kanthal for a single coil to be .5ohms on a 3mm ID rod
so in dual coil you need 2 coils that are 10 wraps

On a tube with a VTC4 0.1ohm is plenty safe just build something that ramps up instantly so you aren't riding the button.

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If I recall correctly, my progression of building (or my descent into darkness, whichever you'd like to call it) ran about like this...


Thin gauge (26ga) standard Coil, thick gauge (22ga) spaced, medium gauge (24ga) parallel, then went for claptons and currently rocking out with aliens. There's one or two that I may have skipped, but I don't really count those because even though I made twisted coils, I never really used them and the other is the caterpillar Coil, which is just too damn tedious for me to pop one out even for display purposes at the moment. Once you have the techniques for these coils down, it's just playtime at that point by trying things such as staged claptons or parallel Clapton builds (awesome series box coils!) and zipper coils and all that good stuff. Currently I'm trying to tinker with ribbon wire and also staggered-fused claptons, but so far both of those ventures seem to be the bane of my existence!


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On a tube mech, I would honestly suggest a little lower ohm. .5 takes forever to ramp up. .2 will be perfectly safe with your batteries and will ramp up much faster. I love my mechs and that it's a great point to vape at with them. I hope you love the mech experience as much as I do

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everything.else.is.taken said:

hi, been using SMOK xcube ultra for a while but just bought my first mech mod and RDA, looking for some clarification on safe coil building before i try anything.
first im using Sony VTC4 18650 2100mAh 30A batteries in a VGOD pro mech and VGOD pro drip RDA with 24g kanthal wire. I have used the online calculators to work out (i think) that .5 ohms at 4.2 volts should only be about an 8.4 amp draw which should be safe as i dont want to push batteries this new into the rebuilding game.
so my questions are
-how many wraps and diameter of coils would yield .5ohms on a single coil?
-how do i calculate safe usage with dual coil builds?
-if im starting at .5phms with 24g wire what would be a safe and decent next step?
any help would be great

Click to expand...

First Sony VTC4 are 23a,not 30a.
Second www.steam-engine.org is your best friend.
Then last but not least I would recommend between 0.2 - 0.25 for the build.

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You can use these.............. 316L Aliens (6)cores and .17ohms/pair ..... Good hitting at 11.5 volts.... You'll pull 56amps


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sorry a bit late replying, i was waiting for all my wires and wicks. cheers was exactly the info i needed to get going.
tried 24g kanthal, 8 wraps gets to about .35 and is pretty nice i guess :/ not much experience to make comparisons

then tried 24g, 2mm wrap paralell 4 wraps gets to about .25 in vaporesso transformer RDA which tastes a bit better. still trying not to get down to low just yet. if i wanted to go for taste over clouds would single or double coils be better? thanks for all the info though

The number of coils isn't what's important. It's a combination of surface area, mass, airflow, chamber size, chimney size, power and juice supply.
Personally I never could find a 0.2ohm build that worked well on a mech but then considering the vape I'm accustomed to, that's not surprising at all.

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fair enough, when you say you never could find a 0.2ohm build that worked well do you mean you usually go more or less resistance? only using the VTC4's at the moment and bought half a dozen of them and a good charger so im not waiting for them to charge but in the future i think il invest in some HB6's or something.

Mattp169 said:

using this
http://www.steam-engine.org/coil.html

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best thing out there that i know of besides vapetool for android

Mines lower. I don't abide by the CDR because I don't hold the fire button down for more than 1 maybe 2 seconds.

When I use tubes it's usually a 4x 28g SS alien or a 6 to 8 ply staggerton with 26g SS frames. 4 wraps, 3mm ID. Otherwise I'm using a Sith v2 and I'd burn up an insulator before I hit the CDR on my HG2s.
I don't recommend going past the CDR unless you're builds have no ramp up and you can get your hit very quickly.
Big or small your build should fire pretty fast and fill your lungs pretty fast (again less than 2 seconds) or your batteries are getting hit harder and your atty/mod will get hot.

i'm an ididot i have to ask CDR = Critical Discharge Rate?

whiteowl84 said:

Mines lower. I don't abide by the CDR because I don't hold the fire button down for more than 1 maybe 2 seconds.

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Great to see that someone else understands the concept of being able to build "ultra sub ohm" and stay safe with the application of quick-firing or pulse-firing! I've been building down to between .07-.12 for over 2 years now with my Mech tubes and have had no issues because I'm aware that vaping style can affect safety. My daily is a set of dual aliens that ohm out at .12 if I use NiChrome 80 cores and between .09-.10 if I use SS316L, but some folks still run for the hills or get bug eyed when they hear that I'm running anything that low. With fresh batteries, I pulse until it gets a bit of a drain and then can do the 1-2 second pulls. Battery of choice is either Aspire 1800mAh or Sony VTC5a, and I think I might have a Samsung 25R still hanging around, too.


You're not drinking water are you?! You realize that stuff is found in antifreeze!?!

whiteowl84, if your saying the builds should ramp up quickly otherwise the batteries are taking a real hit, is that an issue if your using batteries with 20ampCDR and your only pulling 11 or 12?

Continuous Discharge Rate.
It's the amount of current the battery can produce continually and still be able to rid it's self of heat. Basically a 20a CRD means you can pull 20a from the battery till it's dead. We're hitting the battery for just seconds at a time so the amount of "safe" current you can pull is debated. Obviously a battery that can shell off enough heat to provide 20a continuously can provide 22a for just a few seconds but exactly where that line is, no one knows.
That's why every one preaches that CDR to new mech users. Stay in that range till you know how your batteries react and till you can build something that ramps instantly. If you're already 10a over your CDR and you're waiting for that build to heat up but you don't know that your batteries were already hot af, it could be catastrophic.

I use HG2s in everything btw.

thanks whiteowl that was very informative.

everything.else.is.taken said:

whiteowl84, if your saying the builds should ramp up quickly otherwise the batteries are taking a real hit, is that an issue if your using batteries with 20ampCDR and your only pulling 11 or 12?

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It's not going to blow them up if your under the CDR but your battery life is basically just being wasted.
With the builds I use I'm getting quite a bit more power out of a tube than most people have their dual battery regulated mods set to and despite this I can still run a tube for several hours before noticing any dip in voltage at all. Usually I'll rotate 2 or 3 cells at work only to get home and charge them to find that none of them were under 4v.

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so i built dual coils that are about .2ohm and ramp up real quick and decided to use the RDA on my SMOK xcube ultra, the mod is capable of quite a bit so how many watt should i run it at? i have used the steam engine calc and worked out a range but not sure where to start, 30-50, 60-80, 80+?
using a vaporesso transformer RDA with lots of airflow and using hg2's so i have decent capacity

from what i understand, if you want an unregulated box-mod style hit, run it at whatever wattage gets you at 7.49 Volts.

if you wanna be able to take a 5+ second long hit, i'd go to steam engine or the android app vapetool, and figure out what the optimal wattage for that coil is and adjust to your liking. most of the time for me thats up anywhere from 5 to 60 watts(i almost always run multi-metal coils so in my mind, TC is out of the question.).

and to note. mah(milli-amp-hours) is different from Amp output. mah is how many hours it will put out its set milli amperage. so a 3000 mah battery should put out 3amps for 1 hour straight.... unless i'm a total moron on the subject, which theres a decent chance i may be. so don't take my word for it.

everything.else.is.taken said:

so i built dual coils that are about .2ohm and ramp up real quick and decided to use the RDA on my SMOK xcube ultra, the mod is capable of quite a bit so how many watt should i run it at? i have used the steam engine calc and worked out a range but not sure where to start, 30-50, 60-80, 80+?
using a vaporesso transformer RDA with lots of airflow and using hg2's so i have decent capacity

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What ever wattage you want.
The wattage I'll tell you is going to be way too high for most people since I'm used to mechs.

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helmet648 said:

from what i understand, if you want an unregulated box-mod style hit, run it at whatever wattage gets you at 7.49 Volts.

if you wanna be able to take a 5+ second long hit, i'd go to steam engine or the android app vapetool, and figure out what the optimal wattage for that coil is and adjust to your liking. most of the time for me thats up anywhere from 5 to 60 watts(i almost always run multi-metal coils so in my mind, TC is out of the question.).

and to note. mah(milli-amp-hours) is different from Amp output. mah is how many hours it will put out its set milli amperage. so a 3000 mah battery should put out 3amps for 1 hour straight.... unless i'm a total moron on the subject, which theres a decent chance i may be. so don't take my word for it.

Click to expand...

TC is out of the question for me, too. But if─for whatever the reason you might have─you like big coils that have a shit ton of metal in them, then there's going to be ramp up. So then what I like to do is just use Arctic Fox firmware─on my Wismec Reuleaux RX300─because that enables me to dial in a custom power curve the purpose of which is to use it in VW mode... so it's just a preheat, no TC. By comparison, preheat on most regulated mods is half assed, if not somewhere in between half assed and totally assed. The beauty of Arctic Fox is in the fact it lets you define your own curve by creating a timeline that uses simple dots, each dot representing a percentage value. It means you could, for example, make it so it starts off at 110 percent, jumps up to 122 percent a tenth of a second after that, peaks to 128 percent after yet another tenth of a second, gradually backs off to 124 percent one more tenth of a second after that, and then─after a tenth of a second again─relaxes to 104 percent before the final, smooth, transition to 100 percent. With a single coil alien that's 7 wraps 3.5mm ID 28/38 Ni80 that ohms out at .5 ohms you'll most definitely notice the difference not only in the ramp up time, but in the flavor production too.

As for using mech mods, I absolutely love them, but my VTC5A batteries get discharged rather quickly because on my single battery tube mechs I am using small dual coil aliens that ohm out at .1 - .11 ohms. I could decide to go for the VTC6 instead, but the reason I don't do that is because the VTC6 is only a 19 amp battery so the battery would heat itself up a lot faster... which I really really don't like. This is one important part of the reason why I had decided to grab the Vaperz Cloud XXX mod (and the XTension tube to go with that─because I just happen to be someone who thinks there's something that can be said for series mechs). Those iJoy 20700 batteries aren't bad.

I use 20a HG2s, only use mechs and get great battery life and my cells might get slightly warm but no more than they did in regulated mods.

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whiteowl84 said:

I use 20a HG2s, only use mechs and get great battery life and my cells might get slightly warm but no more than they did in regulated mods.

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Sure, but... I've been chain vaping the fucking crap out of my VTC5As. The HG2 or 30Q would have lasted me only a couple of months due to excess wear and tear that extra heat would inflict on those 3000 mAh batteries, and, more importantly on top of that, there's the fact the VTC5A is still THE hardest hitting 18650 battery available to us.

I've been using them since I started vaping. I've had these for 6 months. 0.1ohm is nothing compared to what I do to them.
There is no hardest hitting battery. They'll all do about the same thing at the same load. The vtc4 can go a smidgen lower.

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whiteowl84 said:

I've been using them since I started vaping. I've had these for 6 months. 0.1ohm is nothing compared to what I do to them.
There is no hardest hitting battery. They'll all do about the same thing at the same load. The vtc4 can go a smidgen lower.

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No, 0.1 ohms is not nothing compared to what you do with them. That's just because I haven't told you what I really mean when I say "chain vaping".
There is a hardest hitting battery. Some people might not feel much of a difference, but it can be measured, so it's certainly no fantasy, and, personally, I, can feel the difference... a LOT.

Carambrda said:

By comparison, preheat on most regulated mods is half assed, if not somewhere in between half assed and totally assed.

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ahhh, like the half-assed version my sigelei fuchai 213 plus has.

helmet648 said:

ahhh, like the half-assed version my sigelei fuchai 213 plus has.

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Yes obviously. It can be used in VW mode, but only the wattage and the duration of the preheat are adjustable... there's no capability to store multiple different settings, no custom power curves... no nothing excepting the fancy colored screen and the temp control, which I'll never use due to the type of coil builds I prefer. Despite this, it can still be a great mod to a lot of people I'm sure, but unfortunately that changes nothing of what I already said about custom curves.

only reason i got it was because of it being regulated, and the fact i was getting it for $80usd with two VCT4 batteries at a local shop. mind you i know i could have ended up with a better deal online, but i didn't want to wait for shipping.